Methods and Devices for Delivery of Prosthetic Heart Valves and Other Prosthesis

ABSTRACT

Prosthetic valves and their component parts are described, as are prosthetic valve delivery devices and methods for their use. The prosthetic valves are particularly adapted for use in percutaneous aortic valve replacement procedures. The delivery devices are particularly adapted for use in minimally invasive surgical procedures. The preferred delivery device includes a catheter having a deployment mechanism attached to its distal end, and a handle mechanism attached to its proximal end. A plurality of tethers are provided to selectively restrain the valve during deployment. A number of mechanisms for active deployment of partially expanded prosthetic valves are also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/363,961, filed Feb. 27, 2006, which claims the benefit of U.S.Provisional Application Ser. No. 60/548,731, filed Feb. 27, 2004, andU.S. Provisional Application Ser. No. 60/559,199, filed Apr. 1, 2004,each of which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to medical devices and methods.More particularly, the present invention relates to methods and devicesfor delivering and deploying prosthetic heart valves and similarstructures using minimally invasive surgical methods.

BACKGROUND OF THE INVENTION

Diseases and other disorders of the heart valve affect the proper flowof blood from the heart. Two categories of heart valve disease arestenosis and incompetence. Stenosis refers to a failure of the valve toopen fully, due to stiffened valve tissue. Incompetence refers to valvesthat cause inefficient blood circulation by permitting backflow of bloodin the heart.

Medication may be used to treat some heart valve disorders, but manycases require replacement of the native valve with a prosthetic heartvalve. Prosthetic heart valves can be used to replace any of the nativeheart valves (aortic, mitral, tricuspid or pulmonary), although repairor replacement of the aortic or mitral valves is most common becausethey reside in the left side of the heart where pressures are thegreatest. Two primary types of prosthetic heart valves are commonlyused, mechanical heart valves and prosthetic tissue heart valves.

The caged ball design is one of the early mechanical heart valves. Thecaged ball design uses a small ball that is held in place by a weldedmetal cage. In the mid-1960s, another prosthetic valve was designed thatused a tilting disc to better mimic the natural patterns of blood flow.The tilting-disc valves had a polymer disc held in place by two weldedstruts. The bileaflet valve was introduced in the late 1970s. Itincluded two semicircular leaflets that pivot on hinges. The leafletsswing open completely, parallel to the direction of the blood flow. Theydo not close completely, which allows some backflow.

The main advantages of mechanical valves are their high durability.Mechanical heart valves are placed in young patients because theytypically last for the lifetime of the patient. The main problem withall mechanical valves is the increased risk of blood clotting.

Prosthetic tissue valves include human tissue valves and animal tissuevalves. Both types are often referred to as bioprosthetic valves. Thedesign of bioprosthetic valves are closer to the design of the naturalvalve. Bioprosthetic valves do not require long-term anticoagulants,have better hemodynamics, do not cause damage to blood cells, and do notsuffer from many of the structural problems experienced by themechanical heart valves.

Human tissue valves include homografts, which are valves that aretransplanted from another human being, and autografts, which are valvesthat are transplanted from one position to another within the sameperson.

Animal tissue valves are most often heart tissues recovered fromanimals. The recovered tissues are typically stiffened by a tanningsolution, most often glutaraldehyde. The most commonly used animaltissues are porcine, bovine, and equine pericardial tissue.

The animal tissue valves are typically stented valves. Stentless valvesare made by removing the entire aortic root and adjacent aorta as ablock, usually from a pig. The coronary arteries are tied off, and theentire section is trimmed and then implanted into the patient.

A conventional heart valve replacement surgery involves accessing theheart in the patent's thoracic cavity through a longitudinal incision inthe chest. For example, a median sternotomy requires cutting through thesternum and forcing the two opposing halves of the rib cage to be spreadapart, allowing access to the thoracic cavity and heart within. Thepatient is then placed on cardiopulmonary bypass which involves stoppingthe heart to permit access to the internal chambers. Such open heartsurgery is particularly invasive and involves a lengthy and difficultrecovery period.

A less invasive approach to valve replacement is desired. Thepercutaneous implantation of a prosthetic valve is a preferred procedurebecause the operation is performed under local anesthesia, does notrequire cardiopulmonary bypass, and is less traumatic. Current attemptsto provide such a device generally involve stent-like structures, whichare very similar to those used in vascular stent procedures with theexception of being larger diameter as required for the aortic anatomy,as well as having leaflets attached to provide one way blood flow. Thesestent structures are radially contracted for delivery to the intendedsite, and then expanded/deployed to achieve a tubular structure in theannulus. The stent structure needs to provide two primary functions.First, the structure needs to provide adequate radial stiffness when inthe expanded state. Radial stiffness is required to maintain thecylindrical shape of the structure, which assures the leaflets coaptproperly. Proper leaflet coaption assures the edges of the leaflets mateproperly, which is necessary for proper sealing without leaks. Radialstiffness also assures that there will be no paravalvular leakage, whichis leaking between the valve and aorta interface, rather than throughthe leaflets. An additional need for radial stiffness is to providesufficient interaction between the valve and native aortic wall thatthere will be no valve migration as the valve closes and holds full bodyblood pressure. This is a requirement that other vascular devices arenot subjected to. The second primary function of the stent structure isthe ability to be crimped to a reduced size for implantation.

Prior devices have utilized traditional stenting designs which areproduced from tubing or wire wound structures. Although this type ofdesign can provide for crimpability, it provides little radialstiffness. These devices are subject to “radial recoil” in that when thedevice is deployed, typically with balloon expansion, the final deployeddiameter is smaller than the diameter the balloon and stent structurewere expanded to. The recoil is due in part because of the stiffnessmismatches between the device and the anatomical environment in which itis placed. These devices also commonly cause crushing, tearing, or otherdeformation to the valve leaflets during the contraction and expansionprocedures. Other stenting designs have included spirally wound metallicsheets. This type of design provides high radial stiffness, yet crimpingresults in large material strains that can cause stress fractures andextremely large amounts of stored energy in the constrained state.Replacement heart valves are expected to survive for many years whenimplanted. A heart valve sees approximately 500,000,000 cycles over thecourse of 15 years. High stress states during crimping can reduce thefatigue life of the device. Still other devices have included tubing,wire wound structures, or spirally wound sheets formed of nitinol orother superelastic or shape memory material. These devices suffer fromsome of the same deficiencies as those described above.

A number of improved prosthetic heart valves and scaffolding structuresare described in co-pending U.S. patent application Ser. No. 11/066,126,entitled “Prosthetic Heart Valves, Scaffolding Structures, and Methodsfor Implantation of Same,” filed Feb. 25, 2005, (“the '126 application”)which application is hereby incorporated by reference in its entirety.Several of the prosthetic heart valves described in the '126 applicationinclude a support member having a valvular body attached, the supportmember preferably comprising a structure having three panels separatedby three foldable junctions. The '126 application also describes severaldelivery mechanisms adapted to deliver the described prosthetic heartvalve. Although the prosthetic heart valves and delivery systemsdescribed in the '126 application represent a substantial advance in theart, additional delivery systems and methods are desired, particularlysuch systems and methods that are adapted to deliver and deploy theprosthetic heart valves described therein.

SUMMARY OF THE INVENTION

The present invention provides methods and devices for deployingprosthetic heart valves and other prosthetic devices in body lumens. Themethods and devices are particularly adapted for use in percutaneousaortic valve replacement. The methods and devices may also find use inthe peripheral vasculature, the abdominal vasculature, and in otherducts such as the biliary duct, the fallopian tubes, and similar lumenstructures within the body of a patient. Although particularly adaptedfor use in lumens found in the human body, the apparatus and methods mayalso find application in the treatment of animals.

Without intending to limit the scope of the methods and devicesdescribed herein, the deployment devices and methods are particularlyadapted for delivery of prosthetic heart valves and scaffoldingstructures identical or similar to those described in the '126application described above. A particularly preferred prosthetic heartvalve includes a generally cylindrical support structure formed of threesegments, such as panels, interconnected by three foldable junctions,such as hinges, a representative embodiment of which is illustrated inFIG. 1A of the '126 application, which is reproduced herein as FIG. 1A.The exemplary prosthetic valve 30 includes a generally cylindricalsupport member 32 made up of three generally identical curved panels 36and a valvular body 34 attached to the internal surface of the supportmember. Each panel includes an aperture 40 through which extends aplurality of interconnecting braces 42 that define a number ofsub-apertures 44, 46, 48, 50. A hinge 52 is formed at the junctionformed between each pair of adjacent panels. The hinge may be a membranehinge comprising a thin sheet of elastomeric material 54 attached to theexternal edge 56 of each of a pair of adjacent panels 36.

Turning to FIG. 1B-C, a method for transforming a prosthetic valve fromits expanded state to its contracted state is illustrated. These Figuresshow a three-panel support member without a valvular body attached. Themethod for contracting a full prosthetic valve, including the attachedvalvular body, is similar to that described herein in relation to thesupport member alone. As shown in FIG. 1B, each of the panels 36 isfirst inverted, by which is meant that a longitudinal centerline 80 ofeach of the panels 36 is forced radially inward toward the centrallongitudinal axis 82 of the support member. This action is facilitatedby having panels formed of a thin, resilient sheet of material havinggenerally elastic properties, and by the presence of the hinges 52located at the junction between each pair of adjacent panels 36. Duringthe inversion step, the edges 56 of each of the adjacent pairs of panelsfold upon one another at the hinge 52. The resulting structure, shown inFIG. 1B, is a three-vertex 58 star shaped structure, referred to hereinas a “tri-star” shape. Those skilled in the art will recognize that asimilar procedure may be used to invert a four (or more) panel supportmember, in which case the resulting structure would be a four- (or more)vertex star shaped structure.

The prosthetic valve 30 may be further contracted by curling each of thevertices 58 of the star shaped structure to form a multi-lobe structure,as shown in FIG. 1C. As shown in that Figure, each of the three vertices58 is rotated toward the center longitudinal axis 82 of the device,causing each of the three folded-upon edges of the adjacent pairs ofpanels to curl into a lobe 84. The resulting structure, illustrated inFIG. 1C, is a “tri-lobe” structure that represents the fully contractedstate of the prosthetic valve. Those skilled in the art will recognizethat a similar procedure may be used to fully contract a four (or more)panel support member, in which case the resulting structure would be afour- (or more) lobed structure.

The foregoing processes are performed in reverse to transform theprosthetic valve from its contracted state to its expanded state. Forexample, beginning with the prosthetic valve in its “tri-lobe” positionshown in FIG. 1C, the three vertices 58 may be extended radially toachieve the “tri-star” shape shown in FIG. 1B. The “tri-star” shapeshown in FIG. 1B is typically not stable, as the panels 36 tend tospontaneously expand from the inverted shape to the fully expanded shapeshown in FIG. 1A unless the panels are otherwise constrained.Alternatively, if the panels do not spontaneously transition to theexpanded state, it will typically only require a slight amount of forceover a relatively short amount of distance in order to cause the panelsto fully expand. For example, because of the geometry of the three panelstructure, a structure having an expanded diameter of about 21 mm wouldbe fully expanded by insertion of an expanding member having a diameterof only 16 mm into the interior of the structure. In such acircumstance, the 16 mm diameter member would contact the centerline ofeach panel and provide sufficient force to cause each panel to transformfrom the inverted shape shown in FIG. 1B to the fully expanded shapeshown in FIG. 1A. This is in contrast to a typical “stent”-like supportstructure, which requires an expanding member to expand the stent to itsfull radial distance.

Additional details of this and other embodiments of the prosthetic heartvalve and scaffolding structures are provided in the '126 application,to which the present description refers. It is to be understood thatthose prosthetic heart valves and scaffolding structures are onlyexamples of such valves and prosthetic devices that are suitable for usewith the devices and methods described herein. For example, the presentdevices and methods are suitable for delivering valves and prostheticdevices having any cross-sectional or longitudinal profile, and is notlimited to those valves and devices described in the '126 application orelsewhere.

Turning to the deployment devices and methods, in one aspect of thepresent invention, a delivery catheter for prosthetic heart valves andother devices is provided. The delivery catheter is preferably adaptedfor use with a conventional guidewire, having an internal longitudinallumen for passage of the guidewire. The delivery catheter includes ahandle portion located at a proximal end of the catheter, a deploymentmechanism located at the distal end of the catheter, and a cathetershaft interposed between and operatively interconnecting the handleportion and the deployment mechanism. The deployment mechanism includesseveral components that provide the delivery catheter with the abilityto receive and retain a prosthetic valve or other device in acontracted, delivery state, to convert the prosthetic device to apartially expanded state, and then to release the prosthetic valvecompletely from the delivery device. In several preferred embodiments,the deployment mechanism includes an outer slotted tube, a plurality ofwrapping pins attached to a hub and located on the interior of theslotted tube, and a plurality of restraining members that extend throughthe wrapping pins to the distal end of the catheter. Each of thedeployment mechanism components is individually controlled by acorresponding mechanism carried on the handle portion of the catheter.The deployment mechanism preferably also includes a nosecone having anatraumatic distal end.

In several particularly preferred embodiments, the restraining memberscomprise tethers in the form of a wire, a cable, or other long, thinmember made up of one or more of a metal such as stainless steel,metallic alloys, polymeric materials, or other suitable materials. Aparticularly preferred form of the tethers is suture material. Inseveral embodiments, the tethers are adapted to engage the guidewirethat extends distally past the distal end of the delivery catheter. Thetethers preferably engage the guidewire by having a loop, an eyelet, orother similar construction at the distal end of the tether. Optionally,the tether is simply looped around the guidewire and doubles back to thecatheter handle. Thus, the tethers are released when the guidewire isretracted proximally into the delivery catheter. In still otherembodiments, the tethers may be released from the guidewire by actuationof a member carried on the handle mechanism at the proximal end of thecatheter. In still other embodiments, a post or tab is provided on theguidewire, and the tether engages the post or tab but is able to bend orbreak free from the post or tab when a proximally-oriented force isapplied to the tethers.

In a second aspect of the present invention, several optional activedeployment mechanisms are described. The active deployment mechanismsare intended to convert a prosthetic valve, scaffolding structure, orsimilar device from an undeployed, partially deployed, or not-fullydeployed state to its fully expanded state. Several of the activedeployment mechanisms take advantage of the fact that the preferredprosthetic valves and scaffolding structures require only a small amountof force applied any of a large number of points or locations on thevalve or structure in order to cause the valve to fully expand.Exemplary embodiments of the active deployment mechanisms includeembodiments utilizing expandable members that are placed into theinterior of the prosthetic valve and then expanded; embodiments thatoperate by causing the hinges of the undeployed prosthetic valve toopen, thereby transitioning to the fully expanded state; embodimentsthat include implements that engage one or more of the panels to causethe panel to expand to its deployed state; and other embodimentsdescribed herein.

Other aspects, features, and functions of the inventions describedherein will become apparent by reference to the drawings and thedetailed description of the preferred embodiments set forth below.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a prosthetic valve suitable for use bythe delivery catheter of the present invention.

FIG. 1B is a top view of a partially contracted support memberillustrating inverted panels to form a “tri-star” shape.

FIG. 1C is a top view of a fully contracted support member illustratinginverted and curled panels to form a “tri-lobe” shape.

FIG. 2 is a perspective view of a delivery catheter in accordance withthe present invention.

FIG. 3 is a perspective view of a deployment mechanism of the deliverycatheter of FIG. 2.

FIG. 3A is a cross-sectional view of the deployment mechanism shown inFIG. 3.

FIG. 3B is a perspective view of several of the internal componentsincluded in the deployment mechanism shown in FIG. 3.

FIG. 3C is a perspective view of a wrapping pin stabilizer.

FIGS. 3D-F are cross-sectional views of wrapping pins and theirassociated tethers.

FIG. 3G is another perspective view of a wrapping pin stabilizer.

FIG. 4 is a perspective view of a handle mechanism of the deliverycatheter shown in FIG. 2.

FIG. 5 is a cross-sectional view of the handle mechanism shown in FIG.4.

FIG. 6 is a side view of the handle mechanism of the delivery cathetershown in FIG. 2, illustrating several positions corresponding with stepsperformed during use of the delivery catheter to deliver a prostheticdevice.

FIG. 7 is a perspective view of the deployment mechanism, shown with aprosthetic valve in a star shape and with the slotted tube fullyadvanced.

FIG. 8 is a perspective view of the deployment mechanism, shown with aprosthetic valve in a star shape with the wrapping pins fully advancedand with the slotted tube retracted.

FIG. 9 is a perspective view of the deployment mechanism, shown with aprosthetic valve in a star shape with the wrapping pins and the slottedtube retracted.

FIG. 9A is a closeup view of the nosecone and guidewire shown in FIG. 9,showing detail of the manner in which a tether is looped over theguidewire.

FIG. 10 is a perspective view of the deployment mechanism, shown with aprosthetic valve in expanded shape with tethers retaining the valve inplace.

FIG. 11 is a perspective view of the deployment mechanism, shown with aprosthetic valve in expanded shape, and showing the guidewire andtethers withdrawn to release the valve.

FIGS. 12A-B are side cross-sectional and end views, respectively, of aportion of the distal end of a delivery catheter, illustrating an eyeletformed on the ends of each tether.

FIGS. 12C-D are side cross-sectional views of a first wrapping pinhaving no recess, and a second wrapping pin having an eyelet recessformed therein.

FIG. 12E is an end cross-sectional view of a prosthetic valve partiallyrestrained by three dual tethers.

FIGS. 12F-G are illustrations of two methods for selectively attachingdual tethers to a guidewire.

FIG. 13 is a side view of a portion of a delivery catheter illustratinga valve stop formed on each tether.

FIGS. 14A-B are side partial cross-sectional views of a portion of adelivery catheter illustrating tethers including linkage members. FIG.14A shows a valve in its expanded state, and FIG. 14B shows the valve inits “tri-star” state.

FIG. 15 is a side view in partial cross-section of a delivery catheterillustrating tethers having loops that are routed through throughholesin the nosecone.

FIGS. 16A-B are a side view in partial cross-section and an end viewshowing a slotted nosecone.

FIG. 17 is a side view in partial cross-section of a delivery catheterillustrating tethers having primary and secondary sections.

FIGS. 18A-B are side views of a portion of a prosthetic valve havingloops for engaging a tether to prevent migration.

FIGS. 19A-D are side views of several embodiments of wrapping pins.

FIGS. 20A-B are side views in partial cross-section showing a pair (outof three) of articulating wrapping pins, forming a gripper mechanism.

FIGS. 21A-B are an end perspective view in partial cross-section and atop view in partial cross-section of a slotted tube.

FIG. 21C is a side cross-sectional view of a slotted tube having runnersand a valve panel in its contracted state.

FIGS. 22A-B are a perspective view and an end view, respectively, of analternative deployment mechanism for a delivery catheter.

FIG. 23A is an illustration of a shape set nosecone shaft.

FIG. 23B is a cross-sectional end view of the shape set nosecone shaftof FIG. 23A.

FIG. 23C is a side view of the shape set nosecone shaft of FIG. 23Ashowing the tensioning member in tension.

FIGS. 24A-C illustrate a side view in partial cross-section and two endviews, respectively, of an active deployment mechanism for deploying avalve, in accordance with the present invention.

FIGS. 25A-C illustrate side views in partial cross-section of anotheractive deployment mechanism for deploying a valve, in accordance withthe present invention.

FIGS. 26A-E illustrate several embodiments of active deploymentmechanism employing inflatable members, such as balloons.

FIGS. 27A-B illustrates another embodiment of an active deploymentmechanism employing inflatable members, such as balloons.

FIG. 28 illustrates an active deployment mechanism utilizing a rollerand pincher.

FIGS. 29A-B illustrate an active deployment mechanism utilizing a wedge.

FIG. 30 illustrates an active deployment mechanism utilizing a torsionspring.

FIGS. 31A-B illustrate an active deployment mechanism utilizing amembrane balloon mounted on a slotted tube.

FIG. 32 illustrates an active deployment mechanism utilizing a pluralityof linkages able to be expanded by an inflatable member.

FIGS. 33A-B illustrate an active deployment mechanism utilizing anexpansion balloon mounted within the nosecone of a delivery catheter.

FIGS. 34A-C illustrate an active deployment mechanism utilizing a yokeand linkage system adapted to extend radially outward upon actuation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described, it is to be understood thatthis invention is not limited to particular embodiments described, assuch may, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting, since the scope ofthe present invention will be limited only by the appended claims.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which these inventions belong. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present invention, the preferredmethods and materials are now described. All publications mentionedherein are incorporated herein by reference to disclose and describe themethods and/or materials in connection with which the publications arecited.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural referents unless thecontext clearly dictates otherwise.

The publications discussed herein are provided solely for theirdisclosure prior to the filing date of the present application. Nothingherein is to be construed as an admission that the present invention isnot entitled to antedate such publication by virtue of prior invention.Further, the dates of publication provided may be different from theactual publication dates which may need to be independently confirmed.

As will be apparent to those of skill in the art upon reading thisdisclosure, each of the individual embodiments described and illustratedherein has discrete components and features which may be readilyseparated from or combined with the features of any of the other severalembodiments without departing from the scope or spirit of the presentinventions.

A. Delivery Devices and Methods of Use

Devices for delivering prosthetic valves and other devices to atreatment location in a body lumen are described below, as are methodsfor their use. The delivery devices are particularly adapted for use inminimally invasive interventional procedures, such as percutaneousaortic valve replacements. FIG. 2 illustrates a preferred embodiment ofthe device, in the form of a delivery catheter. The delivery catheter100 includes a handle mechanism 102 located at the proximal end of thecatheter, a deployment mechanism 104 located at the distal end of thedevice, and a shaft 106 extending between and interconnecting the handlemechanism 102 and the deployment mechanism 104. The catheter 100 ispreferably provided with a guidewire lumen extending through the entirelength of the catheter, such that a guidewire 108 is able to extendthrough the delivery catheter in an “over-the-wire” construction. In anoptional embodiment (not shown in the drawings), the catheter 100 isprovided with a “rapid-exchange” construction whereby the guidewireexits the catheter shaft through an exit port located near the distalend of the catheter. The cross-sectional profile of the deploymentmechanism 104 and the shaft 106 are of a sufficiently small size thatthey are able to be advanced within the vasculature of a patient to atarget location, such as the valve root of one or more of the valves ofthe heart. A preferred route of entry is through the femoral artery in amanner known to those skilled in the art. Thus, the deployment mechanism104 has a preferred maximum diameter of approximately 24 Fr. It isunderstood, however, that the maximum and minimum transverse dimensionsof the deployment mechanism 104 may be varied in order to obtainnecessary or desired results.

The deployment mechanism 104 is provided with components, structures,and/or features that provide the delivery catheter with the ability toretain a prosthetic valve (or other prosthetic device) in a contractedstate, to deliver the valve to a treatment location, to convert theprosthetic valve to its deployed state (or to allow the valve to convertto its deployed state on its own), to retain control over the valve tomake any necessary final position adjustments, and to convert theprosthetic valve to its contracted state and withdraw the valve (ifneeded). These components, structures, and/or features of the preferreddeployment mechanism are described below.

Turning to FIGS. 3 and 3A, the deployment mechanism 104 is shown in itsfully contracted state for use when the mechanism 104 has not yetreached the target site within the body of a patient, such as prior touse and during the delivery process. The deployment mechanism 104includes a slotted tube 110 that is connected to an outer sheath 112 ofthe catheter shaft 106, such as by way of the attachment collar 111(shown in FIG. 3A). Thus, longitudinal movement or rotation of the outersheath 112 causes longitudinal movement or rotation of the slotted tube110. The slotted tube 110 is a generally cylindrical body that includesa plurality of longitudinal slots 114 that extend from the distal end ofthe slotted tube 110 to near its proximal end. In the preferred deliverycatheter, the slotted tube 110 includes three slots 114 spacedequidistantly about the circumference of the slotted tube 110. The slots114 have a length and width that are sufficient to accommodate theextension of portions of the prosthetic valve 30 therethrough, asdescribed more fully below in reference to FIG. 7, described elsewhereherein. The slotted tube 110 is preferably formed of stainless steel orother generally rigid material suitable for use in medical devices orsimilar applications.

The deployment mechanism 104 may also include a retainer ring 116 and anosecone 118. Although the retainer ring 116 and nosecone 118 are notnecessary parts of the delivery catheter, each of these components mayprovide additional features and functionality when present. The nosecone118 is located at the distal end of the delivery catheter and ispreferably provided with a generally blunt, atraumatic tip 120 tofacilitate passage of the catheter through the patient's vasculaturewhile minimizing damage to the vessel walls. The nosecone 118 ispreferably formed of any suitable biocompatible material. In severalpreferred embodiments, the nosecone is formed of a relatively softelastomeric material, such as a polyurethane, a polyester, or otherpolymeric or silicone-based material. In other embodiments, the noseconeis formed of a more rigid material, such as a plastic, a metal, or ametal alloy material. The nosecone may be coated with a coating materialor coating layer to provide advantageous properties, such as reducedfriction or increased protection against damage. It is also advantageousto provide the nosecone with an atraumatic shape, at least at its distalend, or to form the nosecone 118 of materials that will provide theatraumatic properties while still providing structural integrity to thedistal end of the device. The nosecone 118 preferably includes aplurality of throughholes 122 that extend through the length of thenosecone to allow passage of a plurality of tethers 124, which aredescribed more fully below. A pair of slots 119 are formed on theexterior of the nosecone 118. The slots 119 provide a pair of surfacesfor a wrench or other tool to grasp the nosecone 118 to enable manualmanipulation of the nosecone 118, for purposes to be described below.

The retainer ring 116 is a generally cylindrically shaped ring that islocated generally between the slotted tube 110 and the nosecone 118.More precisely, when the deployment mechanism 104 is in the fullycontracted state shown in FIGS. 3 and 3A, the retainer ring 116preferably overlaps a ledge 126 formed on the distal end of the slottedtube 110. Alternatively, the inner diameter of the retainer ring 116 maybe formed slightly larger than the outer diameter of the slotted tube110, thereby allowing the distal ends of the slotted tube 110 to slidewithin the retainer ring 116 without the need for a ledge 126. In thisway, the retainer ring 116 prevents the distal ends of the slotted tube110 from bowing outward due to pressure caused by the prosthetic valvebeing stored within the deployment mechanism 104.

The proximal end of the retainer ring 116 engages a bearing 128 that isformed integrally with the nosecone 118, and that allows the nosecone118 to rotate inside and independently from the retainer ring 116. Asdescribed below, the slotted tube 110 is rotated relative to thenosecone shaft 136 and the wrapping pins 130 during some operations ofthe deployment mechanism, primarily during the expansion and contractionof the prosthetic valve. Without the bearing 128 (or a suitablealternative), the prosthetic valve would tend to bind up within thedeployment mechanism and prevent relative rotation between the slottedtube 110 and the wrapping pins 130. Thus, the provision of the bearing128 engaged with the retainer ring 116 facilitates this rotation of theslotted tube 110, which engages the retainer ring 116.

Additional features of the interior of the deployment mechanism areillustrated in the cross-sectional view shown in FIGS. 3A-G. A pluralityof fixed wrapping pins 130 are attached to a wrapping pin hub 132 andextend longitudinally from the hub 132 toward the distal end of thecatheter. The preferred embodiment of the delivery catheter includesthree wrapping pins 130, although more or fewer are possible. The hub132 is attached to a wrapping pin shaft 134 that extends proximally fromthe hub 132 beneath the outer sheath 112 of the catheter shaft 106.Thus, movement or rotation of the wrapping pin shaft 134 causeslongitudinal movement or rotation of the hub 132 and the three wrappingpins 130. A wrapping pin stabilizer 133 is slidably attached to theouter surfaces of each of the wrapping pins 130. The pin stabilizer 133is a generally disc-shaped member having a center hole 133 a and threeequally spaced throughholes 133 b to accommodate the three wrapping pins130. As described below, in certain orientations of the deploymentmechanism 104, the pin stabilizer 133 provides support and stability tothe wrapping pins 130 extending distally from the wrapping pin hub 132.

Turning to FIGS. 3D-F, in several of the preferred embodiments, thetethers 124 extend through or are otherwise engaged with the wrappingpins 130. The Figures illustrate several methods by which this is done.In the closed configuration, shown in FIG. 3D, the wrapping pin 130includes a central lumen 131 a through which the tether 124 extends. Thelumen 131 a extends through the length of the wrapping pin 130 andthrough the hub 132, allowing the tether to extend proximally to thehandle mechanism 102. In the open configuration, shown in FIG. 3E, thewrapping pin 130 includes a channel 131 b formed on its underside. Thetether 124 is able to be received in the channel 131 b, although it isnot necessarily retained therein. In the guided configuration, shown inFIG. 3F, the wrapping pin 130 includes a channel 131 b formed on itsunderside. A tether guide 135 is located in the channel 131 b, and ispreferably attached to the handle housing 152 by welding, adhesive, orother suitable method. The tether 124 is routed through the guide 135,and is thereby retained within the guide 135.

A nosecone shaft 136 is located internally of the wrapping pin shaft134. The nosecone 118 is attached to the nosecone shaft 136, and thenosecone shaft 136 is slidably received through the wrapping pin hub132. However, the nosecone shaft 136 is fixed to the wrapping pinstabilizer 133. Thus, longitudinal movement of the nosecone shaft 136causes longitudinal movement of the nosecone 118 and the pin stabilizer133, independent of any of the other components of the deploymentmechanism 104. However, rotation of the handle housing 152 causesrotation of the nosecone 118, the pin stabilizer 133, and the wrappingpins 130. The nosecone shaft 136 is hollow, thereby defining a guidewirelumen 137 through its center.

A plurality of wrapping pin sockets 138 are formed on the proximal sideof the nosecone 118. Each socket 138 is generally cylindrical and has asize adapted to receive the distal portion of a wrapping pin 130therein. When the distal ends of the wrapping pins 130 are engaged withtheir respective sockets 138, the sockets 138 provide support andrigidity to the wrapping pins 130. This support and rigidity isparticularly needed during the wrapping and unwrapping of the prostheticvalve, as described more fully below. During those operations, a largeamount of strain is imparted to each of the wrapping pins 130, whichstrain is absorbed in part by the sockets 138 formed in the nosecone118. Each socket 138 is also provided with a hole 140 that providesaccess to a respective throughhole 122 in the nosecone 118. As describedmore fully below, this provides a passage for a tether 124 that iscontained within each wrapping pin 130 to extend through the hole 140 ineach socket, through the throughhole 122 to the distal end of thenosecone 118.

Although it is not shown in the cross-sectional view in FIG. 3A, aprosthetic valve 30 such as the type described herein in relation toFIGS. 1A-C—and in the '126 application—may be retained on the wrappingpins 130 in the interior of the slotted tube 110. A suitable method forloading the valve 30 into the device will be described below. The valve30 is retained in a contracted, multi-lobe state (see, e.g., FIG. 1C) inwhich each “lobe” is generally wrapped around a respective wrapping pin130, and held in place there by engagement with the interior surface ofthe slotted tube 110.

Turning now to FIGS. 4-6, the handle mechanism 102 will be described.The handle mechanism 102 includes a slotted tube grip 150 that isfixedly connected to the outer sheath 112 while being slidably androtatably mounted on a handle housing 152. The handle housing 152 is agenerally cylindrical hollow shaft. The slotted tube grip 150 ispreferably formed of or covered with a corrugated polymer or rubbermaterial to provide the ability to easily grasp and manipulate the grip150. Similarly, a wrapping pin grip 154, also preferably formed of orcovered with a corrugated polymer or rubber material, is slidablymounted to the handle housing 152. The wrapping pin grip 154 includes abolt 156 that extends through a slot 158 formed in the handle housing152, to engage the proximal end of the wrapping pin shaft 134. A tethergrip 160 is slidably mounted over the proximal end of the handle housing152. The tether grip 160 is also generally cylindrical, having aslightly larger diameter than the handle housing 152, thereby allowingthe tether grip 160 to slide over the handle housing 152 in atelescoping manner. A locking screw 162 extends through a slot 164formed in the tether grip 160 and into the side of the handle housing152 near its proximal end. The locking screw 162 allows the user to fixthe position of the tether grip 160 relative to the handle housing 152by screwing the locking screw 162 down.

Three tether clamps 166 extend from the proximal end of the tether grip160. Each tether clamp 166 is independently clamped to a tether 124 thatextends through the catheter to its distal end, as explained in moredetail herein. Each tether clamp 166 also includes a spring mechanism(not shown) that provides independent tensioning for each tether 124.The proximal end of the nosecone shaft 136 extends out of the proximalend of the tether grip 160, between the three tether clamps 166,terminating in a small cylindrical nosecone shaft grip 168. Theguidewire 108 is shown extending out of the proximal end of the noseconeshaft 136.

The preferred embodiment of the valve delivery catheter so described isintended to be used to deliver and deploy a prosthetic device, such as aprosthetic heart valve, to a patient using minimally invasive surgicaltechniques. Turning to FIGS. 6-11, a representative method of use of thedevice will be described. The device is intended to be introduced to thevasculature of a patient over a standard guidewire that has beenpreviously introduced by any known technique, with access via thefemoral artery being the preferred method. The guidewire is advanced tothe treatment location under x-ray or other guidance, such as to theroot of a heart valve, such as the aortic valve. Once the guidewire isin place, the valve delivery catheter 100 is advanced over the guidewireuntil the deployment mechanism 104 reaches the treatment location.During the delivery process, the deployment mechanism is in the fullycontracted state shown, for example, in FIGS. 2 and 3.

Once the deployment mechanism 104 is located near the treatmentlocation, the valve deployment process begins. The guidewire 108 isinitially left in place through the deployment process, and is notwithdrawn until a particular point in the process defined below. Thevalve deployment process includes manipulation of the slotted tube grip150, wrapping pin grip 154, and tether grip 160 located on the handlemechanism 102, which cause a series of manipulations of the slotted tube110, wrapping pin hub 132 and wrapping pins 130, and the tethers 124, inorder to release and deploy the prosthetic valve in a manner thatprovides control during deployment and the ability to preciselyposition, re-position, and (if necessary) retrieve the prosthetic valveat any time during the deployment process. FIG. 6 illustrates several ofthe positions of the components of the handle mechanism 102 during thepreferred deployment process. These positions correspond to several ofthe delivery steps illustrated in FIGS. 7-11.

As noted elsewhere herein, it is possible to provide valves that arecontracted into other sizes and orientations (such as two lobes or fouror more lobes), which would also include a delivery catheter having adifferent number of slots in the slotted tube 110 and a different numberof wrapping pins 130. For clarity, the present description will focusentirely upon the valve 30 having three panels 36 and three hinges 52,and a delivery catheter 100 having three slots 114 in the slotted tube110 and three wrapping pins 130.

Turning to FIGS. 6 and 7, the first step in deploying the prostheticvalve 30 is to partially expand the contracted valve from the “tri-lobe”shape (see FIG. 1C) to the “tri-star” shape (see FIG. 1B). This is doneby causing relative rotation between the slotted tube 110 and thewrapping pins 130. As shown in FIG. 6, this is done by rotating theslotted tube grip 150 around the longitudinal axis of the deliverycatheter, thereby causing the slotted tube 110 to rotate around thewrapping pins 130, which are maintained stationary. This relativerotation is facilitated by the provision of the bearing 128 in thenosecone 118 of the deployment mechanism 104, as illustrated in FIG. 3A.As the slotted tube 110 rotates relative to the wrapping pins 130, eachof the vertices 58 of the prosthetic valve 30 is caused to extendoutward through its respective slot 114 in the slotted tube 110.Rotation of the slotted tube grip 150 is stopped when the valve 30achieves the “tri-star” shape shown in FIG. 7. At all times during theprocess up to this point, the adjustable components on the handlemechanism (i.e., the tether grip 160, the wrapping pin grip 154, and theslotted tube grip 150) are maintained in position “a”, wherein thetether grip 160 is in its fully retracted position, and the wrapping pingrip 154 and slotted tube grip 150 are each in their fully advancedpositions.

Turning next to FIGS. 6 and 8, the next step in the deployment processis to retract the slotted tube 110 to further expose the prostheticvalve 30. This is done by retracting the slotted tube grip 150 toposition “b” (FIG. 6) while maintaining the wrapping pin grip 154 andtether grip 160 in the same position “b”. Retracting the slotted tube110 causes the valve 30 to become more exposed, but the valve 30 ismaintained in the “tri-star” shape by the wrapping pins 130 whichcontinue to engage each of the three panels 36 of the valve 30. Althoughnot shown in FIG. 8, the distal ends of the wrapping pins 130 alsoremain seated in the wrapping pin sockets 138 located in theproximal-facing portion of the nosecone 118. In this “b” position, thewrapping pin stabilizer 133 is located just proximally of the valve 30and is just distal of the wrapping pin hub 132.

Next, turning to FIGS. 6 and 9, the wrapping pins 130 are retracted byretracting the wrapping pin grip 154 to position “c” (as shown in theFigure, transitioning from position “b” to position “c” requires noadjustment of either the slotted tube grip 150 or the tether grip 160).Retracting the wrapping pins 130 causes the wrapping pins 130 to becomedisengaged from the valve 30 and to retract to the interior of theslotted tube 110. The wrapping pin stabilizer 133, which is fixed to thenosecone shaft 136, slides along the length of the wrapping pins 130until maximum retraction of the wrapping pins 130, which corresponds tothe position shown in FIG. 9, with the stabilizer 133 near the distalends of each of the wrapping pins 130. In this position, the stabilizer133 provides support and rigidity to the nosecone shaft 136, which isotherwise only supported by the wrapping pin hub 132. As shown, forexample, in FIG. 9, the stabilizer 133 effectively decreases thecantilever length of the nosecone shaft 136, thereby providing it withincreased stability. The stabilizer 133 also serves as a backing memberfor the prosthetic valve 30, preventing the valve 30 from movingproximally as the wrapping pins 130 are retracted. Further, thestabilizer 133 also serves as a guide for the tethers 124 as they extendfrom the distal ends of the wrapping pins 130.

The valve remains in the “tri-star” position due to the presence of thetethers 124, the spacing of which is maintained by the holes in thestabilizer 133 through which the wrapping pins 130 and tethers 124extend. In the preferred embodiment shown in FIGS. 9 and 9A, a tether124 extends through each of the wrapping pins 130, through the hole 140in the socket 138, through the throughholes 122 in the nosecone 118, andis looped around the guidewire 108 on the distal side of the nosecone118. The tethers 124 each extend proximally through and within thecatheter shaft 106 and is received and retained in its respective tetherclamp 166 near the proximal end of the catheter 100. In the positionshown in FIG. 9, the tethers 124 are all maintained sufficiently tautthat they retain the valve 30 in the “tri-star” orientation shown in theFigure. This corresponds with position “c” of the tether grip 160relative to the handle housing 152, shown in FIG. 6.

In an alternative embodiment, the tethers 124 may be tensioned bymanipulation of the distal connection of the tethers 124 to theguidewire 108. For example, rotation of the nosecone shaft 136 willcause the tethers 124 to wrap around the guidewire 108, therebyproviding tension to the tethers 124. Other suitable methods fortensioning the tethers 124 are also contemplated, as will be understoodby those skilled in the art.

Turning next to FIGS. 6 and 10, expansion of the valve 30 is obtained byloosening the tethers 124 that otherwise hold the valve 30 in the“tri-star” position. This transition is achieved by advancing the tethergrip 160 to position “d”, as shown in FIG. 6. (Note: Transitioning fromposition “c” to position “d” requires no adjustment of either theslotted tube grip 150 or the wrapping pin grip 154). Advancement of thetether grip 160 relative to the handle housing 152 creates slack in thetethers 124, which slack is taken up by the radial expansion of thevalve 30. In the typical deployment, the valve 30 will automaticallyfully expand to the deployment position shown in FIG. 10 when thetension is released from the tethers 124. For those situations in whichthe valve 30 does not automatically expand, or when the valve onlypartially expands, one or more alternative mechanisms and/or methods maybe utilized to obtain full expansion. Several of these preferredmechanisms and methods are described below in Section B.

It is significant that, in the position shown in FIG. 10, the tethers124 no longer interfere with the expansion of the valve 30, but theyremain in control of the valve 30. In this position, it is possible tomake any final positional adjustments of the valve 30, if necessary.This can be done by simply advancing or withdrawing the catheter 100,which tends to drag or push the valve 30 along with it. This may also befacilitated by slight advancement of the wrapping pin grip 154 and/orretraction of the tether grip 160, each of which actions will tend toapply tension to the tethers 154. In this manner, the valve position maybe adjusted by the user while the valve is in its fully expanded state,under control of the tethers 124.

Alternatively, the valve 30 may be partially or fully contracted onceagain by increasing the tension on the tethers 124, as by retracting thetether grip 160 relative to the handle housing 152. (I.e., moving fromposition “d” to position “c” in FIG. 6). If necessary, the valve 30 maybe fully contracted by retracting the tether grip 160, and then thedeployment mechanism 104 may be fully restored to the undeployedposition by simply reversing the above steps, in order. (I.e., moving toposition “c”, then position “b”, then position “a”). This reversal ofthe process includes a step of advancing the wrapping pins 130 back overthe contracted valve panels as the valve 30 is maintained in the“tri-star” shape. This process is facilitated by the presence of thetethers 124, which act as guides for the wrapping pins 130 to “ride up”over the edges of the valve panels under the guidance of the tethers124. Once the wrapping pins 130 are in place, the slotted tube 110 isadvanced over the valve 30, with each of the vertices of the valve“tri-star” extending through its respective slot 114. The slotted tube110 is then rotated relative to the wrapping pins 130 and valve 30,causing the valve to transition to the fully contracted “tri-lobe” shapefully contained within the slotted tube 110. At that point, the deliverycatheter may be removed from the patient without deploying the valve 30.Any or all of these adjustment or removal steps may be taken, dependingupon the clinical need or depending upon any situation that may ariseduring the deployment procedure.

Turning to FIGS. 6 and 11, assuming that the valve 30 is placed in itsfinal position and is ready to be released, the valve is released fromthe delivery catheter 100 by retracting the guidewire 108 to a positionsuch that the distal end of the guidewire 108 no longer extends past thedistal end of the nosecone 118 of the delivery catheter 100. At thispoint, the tethers 124 are released from their engagement with theguidewire 108. Preferably, the tethers 124 are then retracted at leastinto the wrapping pins 130, and may alternatively be fully retractedthrough and from the proximal end of the delivery catheter 100. This isreflected as handle position “f” in FIG. 6, in which the tether grip 160is retracted at least to its initial position, and no change is made tothe positions of either the wrapping pin grip 154 or the slotted tubegrip 150. As shown in FIG. 11, the valve 30 is completely free from thedelivery catheter 100. The nosecone 118 remains distal of the valve 30,and the nosecone shaft 136 extends through the body of the valve 30.

To complete the delivery process, the delivery catheter is preferablycontracted to its pre-delivery state by advancing the wrapping pins 130into engagement with the nosecone 118 by advancing the wrapping pin grip154 on the handle back to position “a”, then by advancing the slottedtube 110 into engagement with the retainer ring 116 by advancing theslotted tube grip 150 on the handle back to position “a”. At this point,the delivery catheter 100 may be removed from the patient, leaving theprosthetic valve 30 in place.

B. Variations in Construction, Components, and/or Features of DeliveryDevice

Preferred delivery catheters and methods of use are described above. Anumber of variations of several of the components, features, and otheraspects of the device have been contemplated, and are described below.

Turning first to FIGS. 12A-B, an alternative method of connecting thetethers 124 to the guidewire 108 is shown. In the embodiment describedabove, the tethers 124 are looped over the guidewire 108. In theembodiment shown in FIGS. 12A-B, each tether 124 has an eyelet 125formed at its distal end. The eyelet 125 is connected to the tether byan adhesive bond, or by crimping, or by any other suitable method. Eacheyelet 125 has a hole formed at its distal end that is large enough toaccommodate the guidewire 108 extending therethrough. The eyelet 125 mayhave a generally curved shape to rest alongside the nosecone 118, and aterminal end that is generally perpendicular to the longitudinal axisdefined by the guidewire 108.

Turning to FIGS. 12C-D, an optional recess 131 may be formed in thedistal end of each of the wrapping pins 130. The recess 131 ispreferably formed having a shape and size to accommodate the eyelet 125that is optionally provided at the distal end of each of the tethers124. Accordingly, when no recess 131 is available (see, e.g., FIG. 12C),the eyelet 125 may be unable to be withdrawn into the lumen provided forpassage of the tether 124. When a recess 131 is provided (see, e.g.,FIG. 12D), the eyelet 125 is retracted into the recess 131 and does notextend out of the distal end of the wrapping pin 130.

FIG. 12E illustrates an embodiment including a plurality of dual orredundant tethers 124 a-b. As shown in the Figure, a pair of tethers 124a-b are provided on each of the panels of the valve 30. The dual tethers124 a-b may be provided to increase tether strength, where needed, or toprovide redundancy in the case of failure of one of the tethers. FIGS.12F and 12G illustrate two possible methods for attaching the dualtethers 124 a-b to a guidewire 108. In the first method, shown in FIG.12F, a collar 176 is formed near the distal ends of and is attached toboth of the tethers 124 a-b near their distal ends, thereby forming aloop through which the guidewire 108 extends. In this construction, theloop will remain even if one of the tethers fails. In the second method,shown in FIG. 12G, each of the tethers 124 a-b includes a separateattachment loop 178 a-b, through which the guidewire 108 extends. Ineach method, the tethers 124 a-b are released when they are disengagedfrom the guidewire 108 in the manner described above.

Turning to FIG. 13, a valve stop 142 may be provided on each of thetethers 124. Each valve stop 142 is in the form of a small cleat, barb,tab, or other transverse extension from the tether 124. The valve stop142 is intended to provide another mechanism to prevent the valve 30from slipping or migrating relative to the tethers 124 when the tethers124 are in engagement with the valve 30. Thus, the valve stop 142 islocated at a particular known position on each tether 124 to provide anoptimal amount of control to the device 100 when the tethers 124 areengaged with the valve 30.

FIGS. 14A-B illustrate tethers formed of linkages 144 and tethersections 146. Each tether includes an eyelet 125 at its distal endconnecting the tether to the guidewire 108. The eyelet 125 is connecteddirectly to a first linkage member 144 a, which may comprise arelatively rigid member formed of a metallic material, a rigid polymericmaterial, or the like. The linkage 144 is of a length sufficient toaccommodate the valve 30 in its expanded state, as shown in FIG. 14A.The first linkage 144 a is connected to a tether section 146 thatextends through the length of the valve 30, and then connects to asecond linkage member 144 b. The second linkage member 144 b thenconnects to another section of the tether 146, which extends proximallyinto the remainder of the delivery catheter. Each linkage member 144 a,144 b includes a pivot at each end thereof, thereby enabling the linkagemember 144 a, 144 b to pivot relative to the member to which it isattached. Thus, when the tethers are relaxed, the valve 30 is allowed toexpand, as shown in FIG. 14A. However, when the tethers are pulled taut,the linkages 144 a, 144 b pivot, thereby causing the tethers to becometaut and to convert the valve to its “tri-star” shape, as shown in FIG.14B. Preferably, the nosecone 118 is provided with slots thataccommodate the first linkage members 144 a when they are pulled taut inthe position shown in FIG. 14B.

FIG. 15 illustrates a slight variation of the preferred embodimentdescribed above. In this embodiment, the tethers 124 each include a loop148 formed on their distal ends. Each loop 148 is adapted to engage theguidewire 108. The tethers 124, in turn, are routed through throughholes122 formed in the nosecone 118, as described above. Each tether 124 isthen routed through a lumen formed in its respective wrapping pin 130.This particular routing orientation provides a mechanical advantage overother routing orientation because the tethers are captured by thenosecone 118 and wrapping pins 130 in close relation to the valve 30.This orientation also results in less migration of the tethers fromside-to-side relative to the valve 30.

Turning next to FIGS. 16A-B, an alternative method for routing thetethers 124 in and around the nosecone 118 is to provide a plurality ofslots 121 on the exterior of the nosecone 118. Each slot 121 is adaptedto receive and retain a tether 124 when the tethers 124 are pulled taut.The slots 121 also allow the tethers to arise out of and disengage fromits respective slot 121, for example, when the tethers 124 are slack andthe valve 30 expands.

FIG. 17 illustrates another embodiment containing tethers formed of twoseparate components, including a thick, or broad primary tether 124 aand a thin, or narrow secondary tether 124 b. The primary tether 124 amay be formed of a round or flat wire, and may be provided as either astraight component or it may be provided with a degree of shape memory.The secondary tether 124 b may be made from a finer, smaller diametermaterial that is less traumatic to the vessel when it is pulled frombetween the valve 30 and the vessel. The secondary tether 124 b may alsobe more easily retracted through the wrapping pins 130. Although atwo-component tether 124 is shown, it should be appreciated that threeor more components may also be incorporated to make up the tether 124and to obtain various performance characteristics.

Turning next to FIGS. 18A-B, a pair of loops 170 are shown formed on theexternal surface of the valve 30. The loops 170 are intended to providean engagement member on the surface of the valve 30 for the tethers 124to engage to prevent the tethers 124 from migrating on the surface ofthe valve 30. For example, if the tether 124 migrates from thecenterline of a valve panel 36, it may no longer have the ability tocause the valve panel 36 to invert or to restrain it in its invertedshape. By providing the loops 170, such migration of the tethers 124 issubstantially prevented. It will be appreciated that mechanisms otherthan loops 170 may also be provided to restrain tether migration. Forexample, holes, barbs, slots, bumps, or other members may be provided onthe surface or integrated into the body of the valve panel 36 tosubstantially restrain tether migration. One or more such members may besufficient to provide sufficient restraining capability.

Turning to FIGS. 19A-D, several alternative wrapping pin embodiments areillustrated. The alternative embodiments represent several methods bywhich wrapping pin deflection may be overcome. As shown, for example, inFIG. 19A, when the wrapping pin hub 132 is rotated to cause wrapping upof a prosthetic valve 30 by the wrapping pins 130, an amount of torque“T” is imparted to the hub 132, and a corresponding deflecting force “F”is imparted to the distal end of the wrapping pin 130. The deflectingforce “F” tends to cause the wrapping pin 130 to deflect in thedirection of the deflecting force “F”, which tends to interfere with thewrapping procedure. To counteract the deflection force, the wrapping pin130 may be formed having a gradual curving shape, as shown in FIG. 19B,to offset the deflection and to provide more even wrapping of the valve30. The degree and nature of the curvature will vary depending upon thematerials, sizes, and other properties of the delivery device and thevalve, although the curvature will typically be directed toward thedeflecting force. Alternatively, the wrapping pin 130 may be attached tothe hub 132 at a fixed angle, or canted, as illustrated in FIG. 19C.Once again, the cant angle may be determined and will vary. Anotheralternative is shown in FIG. 19D, in which the wrapping pin 130 isprovided with an offset between its proximal and distal ends. Onceagain, the degree of offset may be varied according to need for a givendevice.

Turning to FIGS. 20A-B, in several additional alternative embodiments,the wrapping pins 330 are not fixed in shape or orientation relative tothe hub 332. In several such embodiments, the wrapping pins 330 includearticulating segments 331 connected by rotating joints 332, therebyallowing each wrapping pin 330 to move radially relative to thelongitudinal axis of the device. The concerted movement of the multiplewrapping pins 330 (three pins being preferred, but more or fewer alsobeing possible) allows the structure to act as a gripper formanipulating the prosthetic valve 30. In the preferred embodiments,movement of each articulated wrapping pin 330 is independentlycontrolled, thereby allowing the user to move each articulated wrappingpin 330 independently from a position generally comparable to that ofthe fixed wrapping pins 330 illustrated in the drawings (see FIG. 20A),to a position substantially radially outwardly spaced from thelongitudinal axis of the device (see FIG. 20B). Thus, the close-inposition (FIG. 20A) is suitable for restraining the valve in itscontracted or “tri-star” shape, while the radially spaced position (FIG.20B) is suitable for releasing the valve to its expanded state, or forretrieving the valve from its expanded state in order to transition thevalve back to its contracted state.

FIGS. 21A-B illustrate an alternative construction for the slotted tube110. In this construction, each of the longitudinal members 180 formingthe slotted tube 110 includes an internal base portion 182 formed of arigid material such as stainless steel or other metallic material, or arigid polymeric material. The base portion 182 is intended to providestrength and resiliency to the slotted tube 110 to perform its functionsof receiving, retaining, and manipulating the valve 30 in response tomanipulations of the components contained on the handle mechanism 102 ofthe delivery catheter. Surrounding the base portion 182 of the slottedtube 110 are a number of air gaps 184 and/or filled sections 186 thatare filled with a more flexible, less rigid material relative to thematerial forming the base portion 182. A wide variety of fillermaterials are possible, including several polymeric material such aspolyurethane, or other soft materials such as one or more silicone basedmaterials. The purpose for the air gaps 184 and/or filled portions 186are to provide a less traumatic construction to reduce the likelihood ofcausing damage to the valve 30 or any of its panels 36 or hinges 52while the valve is being loaded, stored, or deployed. By providing anair gap 184 or filled sections 186 on the edges of the longitudinalsections 180 of the slotted tube 110, the valve 30 is more protectedduring roll-up or deployment of the valve, during which time the edgesof the longitudinal members 180 impose force against the valve panels 36to cause them to roll up within the deployment mechanism 104 or todeploy out of the slotted tube 110.

Turning to FIG. 21C, another mechanism for protecting the valve panels36 while they are retained within the slotted tube 110 is comprised of aseries of runners 190 formed on the internal-facing surfaces of thelongitudinal members 180 making up the slotted tube 110. The runners 190provide a raised surface upon which the panels 36 will ride to minimizethe contact between the panels 36 and the slotted tube 110. The runners190 also serve to decrease friction between the two components anddecrease the amount of abrasion that is imparted to the panels.

FIGS. 22A-B illustrate another alternative construction for a portion ofthe deployment mechanism 104 of the delivery catheter 100. In thisalternative construction, the wrapping pins 130 are not needed. Instead,an inner slotted tube 194 is provided coaxially with and interior to theouter slotted tube 110. As the inner slotted tube 194 is rotatedrelative to the outer slotted tube 110, the valve 30 is converted from a“tri-star” shape to a “tri-lobe” shape, as shown, for example, in FIG.22A. Reversing the relative rotation causes the valve 30 to extend outof the slots formed in each of the inner slotted tube 194 and the outerslotted tube 110 to form the “tri-star” shape shown in FIG. 22B. Thevalve 30 may then be deployed by retracting both the inner slotted tube194 and the outer slotted tube 110 relative to the valve 30, therebyallowing the valve to expand to its deployed state.

FIGS. 23A-C illustrate an optional shape set nosecone shaft 136. Theshape set nosecone shaft 136 includes a pre-set shape formed into thedistal end of the nosecone shaft 136 to facilitate the ability for thedistal end of the delivery catheter 100 to pass over the aortic arch.This is particularly useful when the delivery catheter 100 is used fordelivery of a prosthetic aortic valve. The shape set shown in FIG. 23Ais generally in the form of a hook-shape, although other shapes ispossible in order to improve the performance of the catheter. The shapeset is also useful to stabilize the position of the catheter once it isdelivered over the aortic arch. The shape set may be imparted by anymechanical or other method known to those skilled in the art. Anoptional tensioning member 336 may be provided on the external surfaceof the nosecone shaft 136. The tensioning member 336 is used tostraighten the curvature of the shape set nosecone shaft 136 under theuser's control. For example, as a tension force “T” is imparted to thetensioning member 336, such as by the user pulling proximally on thetensioning member 336 from the handle mechanism 102, the nosecone shaft136 is straightened, as shown in FIG. 23C. The operation of thetensioning member 336 thereby provides the ability to manipulate thedistal end of the delivery catheter 100 in a manner that provides anability for the user to effectively steer the catheter over difficult ortortuous portions of the patient's vasculature. Other uses of thetensioning member 336 are described elsewhere herein.

C. Active Deployment of Undeployed and not-Fully Deployed Valves

Although typically a prosthetic valve 30 such as those illustrated anddescribed above in relation to FIGS. 1A-C—and those described in the'126 application and elsewhere—will fully deploy once it is releasedfrom the delivery catheter, it sometimes occurs that the valve does notdeploy, or does not fully deploy. In most of these circumstances, thefailure to deploy or to fully deploy is due to the fact that one or morepanels 36 of a multi-panel valve 30 fails to change from its invertedstate to its expanded state. One such example is illustrated in FIG.24B, in which two panels 36 of a three-panel prosthetic valve 30 haveexpanded, but the upper panel 36 remains in a partially inverted state.Several mechanisms and methods for actively correcting these undeployedand not-fully deployed valves are described herein.

Several of the described mechanisms take advantage of the fact that, inmost circumstances of non-full deployment, only a point contact isneeded to cause the valve to fully expand. Accordingly, it may not benecessary to fully occlude the vessel in order to cause the valve orsimilar prosthetic device to fully expand. Thus, in most of themechanisms and methods described, fluid flow or perfusion is stillallowed through the valve and vessel as the active deployment proceduretakes place. This is to be distinguished from the deployment methodsapplicable to most stent-like prosthetic devices in which fibrillationis induced to decrease flow during the deployment procedure. No suchfibrillation is required for delivery and deployment of the prostheticvalves and similar devices described herein, nor for the activedeployment mechanisms and methods described.

Turning to FIGS. 24A-C, a first such mechanism 200 includes a collar 202and a plurality of wire forms 204 extending proximally from the collar202. The mechanism 200 is intended to ride closely along the noseconeshaft 136 on any of the embodiments of the delivery catheter 100described herein. As the mechanism 200 is advanced distally, it willenter and pass through the body of the partially-expanded valve 30. Onceit is located there, the collar 202 may be retracted proximally, asshown by the arrow “A” in FIG. 24A, thereby causing the wire forms 204to bow radially outward, (see, e.g., FIGS. 24A and 24C), engaging anyinverted panels 36 of the valve 30 and causing them to expand to thefully expanded state. Preferably, the collar 202 is retracted by atether or other control member that is connected to the collar 202 andthat extends proximally to the handle where it can be manipulated by theuser. Once the valve 30 is fully expanded, the collar 202 is advanceddistally to cause the wire forms 204 to return to their unbowed state.The mechanism 200 may then be retracted into the delivery catheter 100.In alternative embodiments, the collar 202 may be provided with threadsthat engage threads formed on the nosecone shaft 136. Any otherengagement providing relative movement between the collar 202 and thenosecone shaft 136 is also suitable.

As an alternative to the wire forms 204 shown in the above embodiment, acontinuous segment of metallic or polymeric material having sufficientelasticity to expand and contract in the manner shown may be used. Otheralternatives including using only a single band or material, or two,three, or more bands. Other alternative constructions and materialscapable of expanding and contracting in the involved space internal ofthe undeployed or partially deployed prosthetic valve 30 are alsocontemplated, and are suitable for use as the active deploymentmechanism 200 described herein.

Another alternative construction for the active deployment mechanism isillustrated in FIGS. 25A-C. A partially deployed valve 30 includes anupper panel 36 that has not yet fully deployed. The deployment mechanism200 comprises a collar 212 and a plurality of wire forms 214 extendingproximally from the collar 212. Prior to use, the collar 212 is locatedinternally of the catheter shaft 106 along the nosecone shaft 136, andthe wire forms 214 lie flat along the nosecone shaft 136 proximally tothe collar 212. (See FIG. 25A). The collar 212 is advanced distallythrough the partially deployed valve 30 until the collar 212 engages theproximal side of the nosecone 118, where further distal advancement isstopped. (See FIG. 25B). As additional distal-oriented force is appliedto the mechanism 200, the wire forms 214 are caused to bow radiallyoutward within the valve 30 to cause the upper panel 36 to fully deploy,as shown in FIG. 25C. The mechanism 200 is then collapsed and retractedproximally.

Turning to FIGS. 26A-E, several alternative balloon-based activedeployment mechanism are described. The balloon-based systems includeuse of a balloon or other expandable member to cause an otherwisenon-fully deployed valve 30 to expand to its fully expanded state upondeployment. Preferably, each of the balloons described herein includesan inflation lumen that is communicatively connected to the handlemechanism 102 or otherwise provided with a mechanism for selectivelyinflating the balloon(s) as needed.

FIG. 26A illustrates a first embodiment in which a balloon 220 isprovided internally of a prosthetic valve 30. The balloon 220 includes apair of broad portions 222 a that correspond with the proximal anddistal ends of the valve 30, and a narrowed waist portion 222 b thatcorresponds with the middle portion of the valve 30. The balloon 220 mayoptionally be provided in a fixed relationship with the valve body, asillustrated in FIG. 26B, wherein the balloon 220 is packaged with thevalve 30 as the valve 30 is loaded into the delivery catheter anddelivered to a treatment location. Thus, if the valve 30 is found not tohave fully expanded after deployment, the balloon 220 may be inflated tocause full deployment.

A number of optional balloon shapes and sizes are illustrated in FIGS.26C-E. For example, in FIG. 26C, a single balloon 220 is shown havingtwo large diameter portions 222 a and a narrow, or smaller diameterportion 222 b connecting the other two portions. In FIG. 26D, a singleballoon 220 is shown, and would preferably extend through the entirelength of the valve 30. In FIG. 26E, three separate balloons 220 a-c areillustrated in an offset-tangent arrangement. The offset-tangentarrangement provides a number of benefits, including the ability toselectively inflate only one or more of the balloons 220 a-c dependingupon which valve panel 36 requires expansion. Also, the offset-tangentarrangement removes the need to fully occlude the vessel, therebyallowing fluid to flow around the balloon structure.

Turning to FIGS. 27A-B, in another alternative arrangement, a pair oftoroidal balloons 226 are attached to the external surface of aprosthetic valve 30 near its proximal and distal ends, respectively. Thepair of toroidal balloons 226 may be selectively expandable in order toactively deploy an otherwise non-fully deployed prosthetic valve 30.Upon expansion of the valve, the balloons 226 may then be deflated andleft in place to serve as a seal against the vessel wall 230, as shownin FIG. 27B. Alternatively, the toroidal balloons 226 may be attached tothe internal wall of the prosthetic valve 30, and may then beselectively detached from the valve 30 after the valve has been fullydeployed.

FIG. 28 illustrates another active deployment mechanism 234 thatincludes a roller member 236 and a pincher member 238, each of which maybe included on the distal end of a shaft that may be included with, orseparate from, the delivery catheter 100. The roller 236 and pincher 238advance along a panel 36 until the components encounter a hinge 52.Because of the diameter of the roller 236 relative to the hinge 52, whenthe roller 236 and pincher 238 engage the hinge 52, they force the hinge52 to open, thereby causing the valve panel 36 to fully deploy.

FIGS. 29A-B illustrate yet another deployment mechanism 242 thatincludes a wedge-shaped member having an upper guide 244 and a lowerseparator 246. As with the previous deployment mechanism 234, thepresent embodiment 242 be included on the distal end of a shaft that maybe included with, or separate from, the delivery catheter 100. The wedgemechanism 242 is intended to be guided onto each of the hinges 52 of theundeployed or not-fully deployed valve 30. Because of the relative sizeand shape of the separator 246 portion of the wedge, the separator 246causes the hinges 52 to open, thereby causing the valve panels 36 toexpand to the fully deployed state.

Turning next to FIG. 30, another deployment mechanism 250 includes atorsion spring 252 mounted to the internal surface of the valve 30. Thetorsion spring 252 may be integrated into and/or may form part of thehinge 52 of the valve 30, but is provided with a pair of arms 254 thatextend into the interior of the valve 30, and which are biased to forcethe valve panels 36 radially outward to fully deploy the valve 30. Thetorsion spring 252 may be formed integrally with the valve 30, in whichcase it remains in place after valve deployment.

Turning to FIGS. 31A-B, yet another active valve deployment mechanism256 includes a membrane balloon 258 formed on or attached to theexternal surface of each of the longitudinal members 180 of the slottedtube 110. The membrane balloons 258 are selectively and independentlyinflatable, as needed to actively deploy one or more undeployed panelsof a prosthetic valve 30. As shown in FIG. 31A, the slotted tube 110 isfirst inserted into the valve 30, then one or more of the membraneballoons 258 is expanded. The expansion is initially to a first state260 in which the membrane balloon engages the valve body panels 36,then, ultimately, to a second state 262 corresponding with full valvedeployment. After deployment, the balloon may be deflated and the deviceremoved from the patient's vasculature.

Turning to FIG. 32, a still further alternative active valve deploymentmechanism 266 includes a plurality of (preferably three) linkage members268, each including a pivot 270 allowing the linkage member to expandradially, such as under the expansion force of an internal balloon 272or other expandable member. Thus, as the deployment mechanism 266 isinserted into the undeployed prosthetic valve 30, it is able to beexpanded by expanding or inflating the balloon 272.

FIGS. 33A-B illustrate another active deployment mechanism 276 thatincorporates a balloon 278 or other expandable member that is formedwithin the internal volume of the nosecone 118. In its undeployed state,shown in FIG. 33A, the balloon 278 does not extend past the distal endof the nosecone 118. However, if needed to expand the undeployed ornot-fully deployed valve 30, the balloon 278 is expanded, as shown inFIG. 33B, thereby expanding the valve 30 to its expanded state.

FIGS. 34A-C illustrate an active deployment mechanism that includes ayoke 282 that is slidably engaged over the nosecone shaft 136. A set ofrotating linkages 284 a-f are connected to the sliding yoke 282 suchthat, when the yoke 282 slides proximally along the nosecone shaft 136,as shown by the arrows “A” in FIG. 34A, the linkages 284 a-f extendradially outward from the shaft 136. In the preferred embodiment, thefree ends 284 d-f of each of the linkages 284 a-f are selectivelyattached to a respective panel of the valve 30 by a temporary mechanism.For example, the free ends 284 d-f of the linkages may be attached tothe valve panels by the tethers 124, such that when the tethers 124 areretracted, the valve panels are released from the linkages 284 a-f. Thenosecone 118 is preferably hollow to accommodate the mechanism prior todeployment.

Another optional active deployment mechanism utilizes the shape setnosecone shaft 136 and tensioning member 336 shown in FIGS. 23A-C. Inthe case of a valve 30 that does not fully deploy, it may be possible tomanipulate the tensioning member 336 to cause either the nosecone 118,the nosecone shaft 136, or some other portion of the deploymentmechanism 104 to engage the undeployed portion of the valve sufficientlyto cause it to fully deploy. In a particularly preferred method, thetethers 124 associated with all of the fully deployed panels are allowedto remain slack, while the tether 124 associated with the undeployedpanel is pulled taut to apply tension to the tether. By doing so, thenosecone 118 and the respective wrapping pin 130 are pulled to therespective distal and proximal edges of the valve panel, creating arelatively rigid linkage between the components. Once this is done, thetensioning member 336 (or other suitable steering mechanism) is actuatedin order to cause the relatively rigid linkage to bias thestill-inverted panel radially outward to the expanded position. Thisprocess may be repeated for each panel that is not fully expanded.

Finally, another alternative active deployment mechanism is topressurize the aorta (or other treatment vessel) to cause the tissuedefining the vessel to expand, thereby providing an adequate (increased)volume within which the valve 30 or other device is able to expand toits fully expanded state. Pressurization of the aorta (or other vessel)may be obtained by simply occluding the vessel, or by activelypressuring the vessel using an external source.

The preferred embodiments of the inventions that are the subject of thisapplication are described above in detail for the purpose of settingforth a complete disclosure and for the sake of explanation and clarity.Those skilled in the art will envision other modifications within thescope and spirit of the present disclosure. Such alternatives,additions, modifications, and improvements may be made without departingfrom the scope of the present inventions, which is defined by theclaims.

1. A method for performing an interventional surgical procedure,comprising: introducing a catheter into the vasculature of a patient,said delivery catheter having an inner shaft and an outer sheathsubstantially surrounding said inner shaft; causing relative rotationbetween said inner shaft and said outer sheath.
 2. The method of claim1, further comprising the step of: deploying a prosthetic device at atreatment location within the patient.
 3. The method of claim 2, whereinsaid treatment location is a blood vessel.
 4. The method of claim 2,wherein said prosthetic device is a prosthetic heart valve.
 5. Themethod of claim 4, wherein said catheter comprises a deploymentmechanism operatively connected to said outer sheath and said innershaft, said deployment mechanism adapted to maintain said prostheticheart valve in a contracted state and to transform said prosthetic heartvalve to a fully expanded state.
 6. The method of claim 5, wherein saiddeployment mechanism includes a first tube having a plurality of slotsattached to said outer sheath.
 7. The method of claim 6, wherein saiddeployment mechanism includes a second tube having a plurality of slotsattached to said inner shaft.
 8. The method of claim 6, furthercomprising a plurality of pins attached to said inner shaft.
 9. Themethod of claim 8, wherein rotation of said outer sheath relative tosaid inner shaft causes rotation of said first tube relative to saidplurality of pins, thereby transforming said prosthetic valve from itscontracted state to at least a partially expanded state.
 10. The methodof claim 8, further comprising the step of: retracting said outer sheathproximally relative to said inner shaft.
 11. The method of claim 10,wherein said retracting step allows said prosthetic valve to transformto its fully expanded state.
 12. The method of claim 11, wherein saiddeployment mechanism includes at least one restraining member adapted torestrain said prosthetic valve in its fully expanded state.
 13. Themethod of claim 12, wherein said restraining member comprise one or moretethers.
 14. The method of claim 12, further comprising the step of:using said at least one restraining member to reposition said prostheticdevice at said treatment location.
 15. The method of claim 12, furthercomprising the step of: using said at least one restraining member toreturn said prosthetic valve to its contracted state within saidcatheter.